Impact-tool



(No Model.) 2 Sheets-Sheet Il* Je l n GT TO No. 573,260. Patented Deo.15, 1896.

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J. P. CLEMENT.

IMPACT TOL No. 573,260. Patented Deo. l5, 1896,

Ffa@ Fjdff UNITED STATES .1

PATENT OFFICE.

JOHN F. CLEMENT, OF PHILADELPHIA, PENNSYLVANIA, ASSIGN OR TO THE CLEMENTPNEUMATIO TOOL COMPANY, OIF

OAMDEN, NEW JERSEY.

, IM PACT-TOOL.

A SPECIFICATION forming part of Letters Patent No. 573,260, datedDecember 15, 1896.

Application filed May 7,1896. Serial No. 590,561. (No model.)A

To all whom it may concern,.-

Beit known that I, JOHN F. CLEMENT, a citizen of the United States,residing in Philadelphia, Pennsylvania, haveinvented certainImprovements in ImpactTools, of which the following is a speciiication.

One object of my invention is to so construct an impact-tool of thevalveless class as to prevent side pressure upon the reciproro eatingpiston or hammer, a further object being to arrest the reciproeation ofthe hammer except when the tool is at Work, and a still further objectbeing to adapt the tool for use with different kinds of chiselsorcutting-tools. Theseobjectslattain in the manner hereinafter setforth, reference being had to the accompanying drawings, in which*-Figure l is a longitudinalsection of anin1- pact-tool constructed inaccordance with my 2o invention. Fig. 2 is a similar view showing thepiston or hammer in a different position. Fig. 3 is a transversesectionon the line 3 3, Fig. l; and Fig. 4 is a View of a special form ofhammer constituting part of my invenz 5 tion.

In Figs. l, 2, and 3, A represents the cylinder of the tool, which hasat the rear end a cap B, lirmly secured thereto by screwing it into theend of the cylinder, a spring-plug d,

3o carried by the cap and adapted to an opening in the cylinder, servingto prevent the unscrewing of said cap un til said plug has been firstpushed inward, so as to be free from engagement with the cylinder. Thecap is bored 3 5 out centrally to receive the enlarged forward end ofthe stem b of a handle F, said stem being seated upon a block or Washerb', of rubber or other elastic material, located at the inner end of theopening in the cap,

4o which block` is slightly compressed by .they stem of the handle, thelatterbeing retained 3 in longitudinal position to insure suchcompression by means of an annular Washer b2, of elastic material,bearing upon the shoulder formed by the enlargement of the stem h,

and retainedin position by an annular retainer D, screwed into the outerend of the cap B. By this means the handle F is confined to the cylinderA in a longitudinal di- 5o rection, but yet is free to turn or swivel onthe cylinder to suit the convenience of the workman using the tool, theelastic cushions preventing any shock yrjar from being transmitted tothehandle. X

Snugly fitting in the bore of the cylinder -5 5 is the reciprocatingpiston or hammer G, which has extending transversely through it anopening f, which is always in communication with an inlet-porti in oneside of the cylinder, this inlet-port communicating 6o in any suitablemanner with a supply of motive fluid under pressure.

In the present instance the tool is intended for use with compressedair, and the inletport i is in vcommunication with a nozzle t, to whichthe aireonveyer pipe is directly applied, but any other available meansof conveying the motive iiuid to the inlet-porti' may be adopted withoutdeparting from my invention. 7o

In the side of the cylinder opposite that having the inlet-port are twodouble-ended conveyer-ports m and n, t-he rear end` of the rear port mcommunicating with the rear end of the cylinder and the forward end ofthe forward port n communicating with the 'forward end of said cylinder.In the cylinder are also formed two exhaust-ports s and t, the port sserving to permit of the escape of motive fluid from the rear end of thecylinder 8o and the port t providing for the escape of motive fluid fromthe forward endof the cylinder, these ports by preference beingindependent of each other and each consisting of inner and outer radialportions connected by a longitudinal passage, so that while they providefor the free escape of motive liuid from the cylinder they will preventthe access of sand, metal chips, or other foreign matters into thecylinder. The rear exhaust-port is 9o preferably of less area than theforward exhaust-port, so as to provide fora freer escape f motive iiuidfrom the front end of the cylinder than from the rear end of the same.

The piston or hammer G has a forwardlyprojecting stem G', which isguided in the for! ward end of the cylinder and acts upon the inner endof the stem or shank H of the chisel or other tool which is being used,the latter being guided in an opening at the forward end roo ot' thecylinder, to which it fits with reasonable snugness. AThe stem G' whenprojected enters a chamber ol, which is of slightly greater diameterthan the opening in whichy said stem is guided and has a lateral ventCW, so as to prevent the possibility of any cushioning of the blow bythe compression of air in advance of the hammer-stem.

In the lower portion of the piston G is formed a right-angled opening w,one portion of which extends to the forward end of the piston, while theother portion extends to one side of the piston in line laterally withthe lower exhaust-port t.

The operation of the tool is as follows Vhen the parts are in theposition shown in Fig. 2, the piston G is at the rear end of its stroke,the port t is uncovered, so as to permit the free escape of motive iiuidfrom the forward end of the cylinder, and the forward end of the port mis in communication with the transverse passage f of the piston, so thatmotive iiuid ows freely from the inlet-port 2'. through said passage,and thence through the port m to the rear end of the cylindeigin orderto drive the piston forward. After the projecting 'stem of the pistonhas delivered its blow upon the inner end of the tool-stem the ports arein the position lshown in Fig. l, the exhaust-port s being now open, soas to permit of the escapeof motive lfluid from the rear end of thecylinder, and the forward port n being in communication with the-transverse passage f of the piston, so that motive fluid is directed tothe forward end of the cylinder in order to drive'the piston rearwardtherein, this rearward movement continuing until the parts again assumethe position shown in Fig. 2, prior to a repetition of thebefore-described operations. Vhen the cutting-tool is not being used, oris not pressed firmly against the work, the piston or hammer G will onits forward movement meet with no resistance, or less than the normalamount of resistance, from the tool, and hence will pass forward beyondits normal point, thus opening communication between the'passage w inthe piston and the exhaust-port t. The air which had entered the forwardend of the cylinder before the piston completed its excessive forwardstroke escapes therefrom through the passage fw and exhaust-port t, sothat after the port t' is closed `by the forward movement of the pistonthere is no pressure'in the forward end of the cylinder to drive saidpiston rearward. vHence the parts will remain inoperative until the toolis again pressed upon the. work with sufficient force to move the pistonbackward to such an extent as to again open the inlet-port t'.

In the construction shown in Fig. -t the piston G2 is provided withadetachable stem G3, which is intended to be of such length that itsforward end will project beyond the cylinder, so that it can be adaptedto a socket at the end of the tool-stein, as shown by dotted lines, theforward end ofthe stem G3 also by preference having a socket formed init, so that it can be applied to an ordinary toolstem as well, ifdesired. By forming a passage directly through the piston from one sideto the other for the conveyance of motive fluid from the inlet-port tothe conveyer-ports of the cylinder I avoid side pressure, whichinvariably results when the passage is in the form of an annular groovein the piston and which is due to the impingement of the motive fluidupon t-he central or reduced portion of the piston. I therefore reducethe friction upon the piston and facilitate the reciprocation of thesaine and at the same time prevent wear of either piston or cylinder dueto the lateral lpressure upon said piston.

Having thus described my invention, I claim and desire to secure byLetters Patent- 1. The combination in an impact-tool, of a cylinderhaving an inlet-port, and conveyerports, one of the latterycommunicating with one end of the cylinder and the other with theopposite end of the same, with a piston reciprocating in said cylinderand having an opening transversely through it which serves to convey themotive fluid from the inlet-port to the rconveyer-ports alternately asthe piston is reciprocated, whereby side pressure upon the piston isprevented.

2. The combination in an impact-tool, of a cylinder having aninlet-port, conveyer-ports, one communicating with one end of thecylinder, and the other with the opposite end of the same, andexhaust-ports for the opposite ends of the cylinder, with a pistonreciprocating in said cylinder and serving by its movements to directmotive fluid first to one end of the cylinder, and then to the other endof the same, and an escape-passage formed in said piston and serving toopen communication between the forward end ofthe cylinder and theforward exhaust-port, on excessive forward movement of the piston in thecylinder.

3. The combination in an impact-tool, of a cylinder, ya pistonreciprocating therein, and a stern detachable from said piston, andprojecting forwardly beyond the cylinder, said stem being constructed atits forward end for the reception of a tool-stem.

4. The combination of the cylinder, with the vhan dle'confinedlongitudinally to the cylinder, but free to turn independently thereof.

5. The combination of the cylinder, with the handle having an elasticlongitudinal connection with the cylinder but free to turn in respect tothe cylinder.

G. The combination lof the cylinder, with the handle having a stem withenlarged end, elastic blocks or washers engaging the forward and rearportions of said enlargement of the stem, and a confining-rin g for saidrear washer.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN F. CLEMENT.

Witnesses:

F. E. BEcHToLD, J os. H. KLEIN.

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